Gwen Stefani's oldest son is growing up fast and he looks so much like his dad, Gavin Rossdale, it’s scary.The No Doubt singer shares her three children with her ex-husband and teenager, Kingston, is the spitting image of his rocker father. MORE: Gwen Stefani and Blake Shelton's unique living situation revealedGavin recently shared a throwback video of himself on Instagram rocking out with his band, Bush, and the similarity to his 14 year old was uncanny.Fans have regularly noted the resemblance